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MIB Parsing Issues (v2.0.2)

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Remington Campbell edited this page Jul 29, 2020 · 4 revisions

MIB parsing is not verified in TDM. It needs to be revisited with domain expertise.

OIDs missing.

The number one issue here is that there are OIDs missing from what is loaded in to TDM. This implies that our MIB parsing is to some degree incorrect. For instance, OSPF-MIB or ciscoFlashPartitionEntry. We must inspect the intermediary files which are compiled from the MIBs to determine if this is an issue with the way we traverse the intermediary formats exposing OIDs, the way we are parsing the OIDs themselves with pysmi, or fundamentally with the MIBs themselves.

Overlapping OIDs.

There are OIDs which appear to overlap each other which breaks the TDM schema tracking numeric OID as machine_id. e.g.

etl_1       | ERROR:root:Duplicate oid 1.3.6.1.4.1.351.110.6.2.6 from BASIS-RAS-DISK-MIB in CISCO-MGX82XX-DSX3-BERT-MIB!
etl_1       | ERROR:root:Duplicate oid 1.3.6.1.4.1.351.110.6.2.7 from BASIS-RAS-DISK-MIB in CISCO-MGX82XX-DSX3-BERT-MIB!
etl_1       | ERROR:root:Duplicate oid 1.3.6.1.4.1.351.110.6.2.8 from BASIS-RAS-DISK-MIB in CISCO-MGX82XX-DSX3-BERT-MIB!
etl_1       | ERROR:root:Duplicate oid 1.3.6.1.4.1.353 from ATM-SOFT-PVC-MIB in IMA-MIB!
etl_1       | ERROR:root:Duplicate oid 1.3.6.1.4.1.353.5 from ATM-SOFT-PVC-MIB in IMA-MIB!

These entire trees will likely not make it in to TDM as a result.

Uncertain pysmi usage.

The current SNMP ETL implementation uses pysmi to compile the MIBs to a JSON output. How this works isn't very well understood, and there are various overrides to ignore errors, etc. The outputs were never inspected for correctness. Now that gaps in what is present have been identified it is time to inspect the intermediary files which are emitted by the code, and determine if options are missing from how we parse using pysmi or if it is a more fundamental data issue with the MIBs themselves.

If this is not reconcilable we may need to attempt to source information from other tooling such as the Cisco SNMP Object Navigator, or another third-party MIB source (of which there are many).

OID DataPaths not linked to Release/Device(s).

OID DataPaths are currently not linked to any Releases due to support lists not being easily machine parse-able in a common manner. The support lists at ftp://ftp.cisco.com/pub/mibs/supportlists/ appear to be largely human/hand-written and do not provide enough information to derive actual product support with pointers such as "Please note that not all objects are supported in all of the listed MIBs. Please consult the documentation for further information on MIB object support." on even recent documentation. There is an inherently human expectation for deriving what MIBs are supported which must be resolved before more advanced manageability-of-manageability tooling can be built.

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